1. Field of the Invention
The technical scope of the invention is that of devices to ensure the deconfinement of an ammunition casing enclosing an explosive load and more particularly deconfinement devices for an explosive projectile body, whatever the caliber or type of weapon firing this projectile.
2. Description of the Related Art
Deconfinement devices enable the detonation of a projectile to be avoided further to overheating, for example during a fire.
When an explosive load is overheated, its breakdown generates gases which are trapped inside the projectile casing.
The pressure builds up strongly and causes the projectile to detonate.
It is known to provide deconfinement devices which enable such gases to be evacuated out of the projectile so as to avoid this build-up in pressure eventually leading to detonation.
Patent DE2131748 thus describes a closing plug for a projectile body which is put into position when the projectile is being stored. This plug incorporates a closing plate linked by a fusible material. The build up of temperature releases the plate thereby enabling the gases to evacuate.
However, such deconfinement means may only be implemented during a storage phase of the projectile, phase during which the fuse is dismounted.
Today, such protection is sought even for a projectile still carrying its priming fuse.
In this case, overheating can lead both to the ignition of the load itself further to a build-up in the pressure, and to the ignition of the fuse thereby also causing the explosive load to detonate.
A device is also known by patent FR2864219 that enables deconfinement when the fuse is mounted in the projectile body.
This device comprises a connecting ring that provides a link between the fuse and the projectile, such ring having radial vents inside which silicon plugs are arranged.
Although it is interesting, this device is, however, insufficiently effective since the total surface area of the vents is too small and does not enable a rapid deconfinement of the inside of the projectile body.
A device is also known by patent U.S. Pat. No. 5,035,181 to fasten a fuse to an ammunition body, such device incorporating a ring attached to the ammunition body by a layer of fusible material that melts further to an increase in the temperature. After fusion, the ring carrying the fuse is ejected by the action of a compression spring.
Such a device is complicated in that it implements a spring held in a compressed state. The mechanical strength of the fusible material is, furthermore, not ensured, namely after long period of storage, thereby endangering the reliability of this device.
Lastly, an impact marking projectile is known by patent DE4336808 that incorporates a fuse able to be ejected during the trajectory through the actions of a specific pyrotechnic charge. However, such a projectile does not incorporate an explosive load. With such a projectile, the problem of the protection of a load against increasing temperatures is not raised. Furthermore, the structure described is not adapted to the ignition of an explosive load.